Fluid circulation is a common and efficient way of cooling machines and processes. Fluid coolant is circulated in fluid connection with a heat source, whereby heat is conducted away from the source by virtue of the heat conductive properties of the coolant fluid. A typical cooling application of fluid circulation is the cooling of motors, wherein conventional circulation systems are adequate.
However, it is more and more frequently the case that cooling circulation is desired for applications that reside in remote and demanding locations. One example of such an application is wind turbines. In addition to electricity, wind turbines generate a considerable amount of waste heat, which require efficient cooling. As wind turbines are generally located in remote locations and high above ground level, the maintenance of the cooling system is challenging.
Conventional fluid circulation cooling systems are, however, quite vulnerable malfunctions. Conventional systems may fail due to the effect of the cooling liquid being in contact with the piping and seals of the system. The cooling liquid can particularly cause corrosion, erosion in sections of the circulation having high flow or concentration in sections of the circulation having slow flow. If the cooling circulation system of the frequency converter of a wind turbine, for example, were to fail, also the frequency converted would fail and the process would seize. As wind turbines are difficult to reach, the failure would lead to a significant downtime and loss of profits.
Solutions have been created for noticing a failure in such cooling systems. However, as explained above, it would be desirable to anticipate probable failures such that the remote location is reached in time. In order to anticipate such failures and appropriate maintenance actions, special analysis systems have been created. These known analysis systems measure the corrosion rate of sacrificial sensor material and based on the corrosion rate, the system derives the probable failure time for the specific circulation piping. Such analysis systems are, however, rather complicated, expensive and require considerable adaptation efforts. In addition, the output represents a mere mathematical assessment of the probable failure. As a result, such systems are not ideal for applications in remote and demanding locations, such as in cooling the frequency converter of a wind turbine.